Tractor



' Y 4 Sheets-Sheet 7e* H. s. EBERHARD v TRACTOR Filed Jan. 18, 1932 Oct. 1, 1935.

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TRACTOR Filed Jan. 18, 1932 4 Sheets-,Sheet 4 WIW A ORNY. f.

Patented oct.' 1, 1935 UNITED l STATES PATENT OFFICE TRACTOR Harmon S. Eberhard, San Leandro, Calif., as-

signor to Caterpillar Tractor Co., San Leandro, Calif., a corporation of California vApplication January 18, 1932, Serial No.-!58'i,258 23 claims. (c1. 305-9) This invention is concerned with the construction of a tractor and particularly one of the track type. Such tractors are 'generally characterized by the inclusion of a main frame con` veniently formed by the power plant of the tractor, and a pair Vof truck frames carrying tracks upon opposite sides of the main frame. It has been found desirable to fabricate the tractor in such a manner that each truck frame is constrained to movement in a plane parallel to a vertical plane containing the longitudinal axis of the main frame. In other words, it is desired that the truck frames be permitted to oscillate with respect to the main frame, but thatall lateral movement of a truck frame with respect to the main frame be substantially prohibited. If the truck frame moves at all laterally, partic-v ularly the front end ofthe truck frame, it places a great stress upon the rear hinge connection between the truck frameand the main frame. The

present invention is particularlyadvantageous -where the truck frame is hinged concentrically lwith a drive sprocket..

It is in general the object of the present invention to provide a tractor construction in which\ the movement of the truck frames with respect to the main frame is limited to oscillatory movement, all lateral movement being substantially prohibited. z

Another object of the invention is to provide for the connection of the main frame of a tractor and the truck frames to permit equalization of the movement of the truck frames with respect to the main frame, while positively restraining the truck frames against lateral movement The invention possesses numerousl other objects and features of advantage, some of which, with the foregoing, will appear at length in the following wherein I-Wi1l disclose a preferred form of my invention:

Description of drawings 'In the drawings, Fig. 1 is a side elevation of a tractor embodying the construction of my invention.

Fig. 2 is a plan view illustrating connection of the main frame to the truck frames and equalizer bar, parts being shown in section.

Descmptic-mv of preferred mechanism In the form of tractor shown, I have depicted a machine in which the power units of the tractor are assembled as one physical body. Thus, en-

-gine 5 (Figs. 1 and2) 'and transmission unit] are so fabricated that 'they constitute a unitay power plant whichis used as main frame 5 of the tractor. l

Power initially derived from engine 6 ,and

transmitted through transmission unit 1, is sup- 5 plied (Figs. 1 and 3) to drive sprockets 8, arranged upon opposite sidesof the tractor. Drive sprockets 8 (Figs. 1, 3, and 4) r-e in engagement with chains 9 which carry track shoes I0 assembled to provide ground-engaging tracksnl Chains 9 (Figs. 1 and 3) are carried over idler wheel II positioned at the forward end of truckframes I2. Sprockets 8 and wheels II are respectively positioned at opposite ends of each truck frame I2 so that several track shoes I0 enl15 vgage the surface of the ground at one time.

Ground-engaging portions of chains 9 (Figs. 1,

3, and 4) are engaged with track rollers I3 (Figs.

1 and 4) which serve to support the weight of the tractor on chains 9. Rollers I3 are positioned in 20 bearings I4 upon truck frames I2.

Means are provided on main frame 5 to secure truck frames I2 for oscillatory movement with respect to main frame 5 and to prohibit all other movementwith respect to main frame 5. Each 25 truck frame I 2 is hinged by bracket II on stub axle I6 in main frame 5. Sprockets 8 revolve about the axis of axles I6, truck frames I2 thus I1, while the inboard side is cut oi to permit each truck frame to hinge on stub axle I 6. Transmission case I (Fig. 2) includes `housings 4l which enclose the usual steering clutches for 35 the tractor, while housing portion 42 contains the usual bevel gear drive of thetractor. Housing portion 42 is spaced from housing 4I to provide apertures 43.

Tapered stub axles I6 extend through and are 40 secured in housings 4I (Fig. 2) by nuts 44 which engage a 'threaded portion on each axle to draw tapered axle portions 46 into engagement with housings 4I. Stub axlesIB extend through. apertures 43 and into housing portion 42.` Tubular 45 arms I8 are fastened by bearings I9 on that portion of stub axles I5 in apertures 43 (Figs. 2 and 3). Arms I8 extend forwardly and terminate in bracket 41 which is fastened upon the inboard side of truck frames I2 by bolts 20 (Figs. 3 and 4) 50 Truck frames I2 are thus positioned for hinging about axles I6. Arms I8 prevent motion other than that of merely hlnging upon axle I6, Vand lateral stresses set up at this end of the tractor are transmitted and distributed to main frame 5 55 at points which can be madeamply strong.

The other ends of truck frames I2 are connected to main frame 5 in such a manner that, while truck frames I2 are free to oscillate about axle I6,

lateral movement is prohibited. crankshafts 24 60.

(Fig. 5) are fastened in bearings 25 upon the truck frames I2. Nut 43 prevents slidingmovement of each crankshaft 24 in each bearing 25. Crank .arm 23 normally extends vertically from crankshaft 24. Crank pin 22, on crank arm 23, is journalled in end 49 of link member 2|. Crank pin 22 is prevented from sliding in link end 49 by nut 5|. Link members 2| are journalled by bearings 31 on shaft 26 which extends through bearing 21 on crankcase 32 of engine 6. Nuts 52.prevent sliding movement of link members 2| on shaft 26. Link members 2l extend forwardly and carry brackets 35 which are hinged by pins 53 on link members 2|.

To transmit motion of one link member 2| to the other link member so as to equalize movement of one.truck frame I2 relative to the other truck s frame I2 and main frame 5, inverted spring 33 is extended between brackets 35 with spring ends 34 in brackets 35. (Figs. 2 and 4). Spring 33 is suspended in and fastened to bracket 28 by U -bolts 29 passed about spring 33 and over pads 36. Bracket 28 is hinged on pin 30 which is carried in lugs 3| on crankcase32. Spring 33 thus serves as a link which together with link members 2| support the` front end of the main frame on the' truck frames. Also, by using spring 33 between link members 2|, movement of a truck frame is cushioned. However, a solid bar can be usedl in place of spring 33 to connect link members 2| and serve as an equalizer bar or link.

Oscillation of one truck frame I2 is thus transmitted to the other truck frame I2 so that main frame 5 only moves through half the distance that an oscillating truck frame moves. At the same time, any lateral displacement of a truck frame" frame/s I2 rotate about axis of axles I6, link members 2| and truck frames I2 follow different oscillatory paths, generally non-coincident, about their different axes of rotation. Crankshaft 24, crank arms 23, and crank pins 22 provide a connection which enables link members 2| and tuck frames I2 to follow their non-coincident oscillatory paths, at the same time prohibit- -ing lateral displacement between a track frame I2 and main frame 5.

'I, therefore, claim as my invention:

l. In a tractor, a main frame, a pair of-truck frames on opposite sides of said main frame and hingedly connected thereto, means for connect- Ving said truck frames to said main frame to permit only oscillatory movement of said main frame relative to safd truck frames, and an equalizer bar mounted on said main frame and sli'dably -engaging said connecting means.

`2. In a tractor, a'main frame, a pair of truck frames, load supporting connections between the rear end of said main framefand said truck frames, and load supporting connections between .the front end of vsaid main frame? and said truck frames; said latter load supporting connections comprising cooperating links connected together and mounted on the front of said main Relative movement beframe on substantially horizontal pivots having axes substantially normal to each other.

3. In a tractor, a main frame, a pair of truck frames, load supporting connections between the rear end oi said main frame and said truck frames, and load supporting connections between the front end of said main frame and said truck frames; said latter load supporting connections comprising a lever at each' side of said main frame movably connected to a truck frame and l0 to said main frame, an equalizer bar positioned adjacent the front end of said main frame and connected with said levers, and means for pivotally connecting said equalizer bar to said main frame for movement about a substantially horiL 15 zontal axis.

4. In a tractor, a main frame, a pair of truck frames, load supporting connections between the rear end of said main frame and` said truck frames, and load supporting connections between 20 the front end of said main frame and said truck frames; said latter load supporting connections comprising substantially straight levers one at each side ofA said main frame and adjacent the front end thereof, means for movably connect- 25 ing an end of each lever to a truck frame, means for pivotally connecting each lever intermediatey its, endsto said main frame, an equalizer bar positioned adjacent the front of said main frame, and means connecting each end of said equalizer 30 bar to a lever.

5. In a tractor, a main frame, a pair of truck frames, load supporting connections between the rear end of said main frame and said truck `frames,'and load supporting connections between 85 the front end of; said main frame and said truck frames; said latter load supporting connections comprising substantially straight levers one at each side of said main frame and adjacent the front end thereof, means for movably connect` 40 ing an end of each lever to a truck frame, means for'pivctally connecting each lever intermediate its endsy to said main frame, an equalizer bar positioned under and adjacent the front of said main frame, said equalizer bar extending trans- 45 versely of said main frame and being connected to said levers at the ends thereof opposite to the ends connected to said truck frames, and means for pivotally connecting said equalizer bar to `the main frameV fer movement about a sub- 5o stantially horizontal axis. r

6. In a tractor, a main frame, a pair of spaced truck frames each movably connected to said main frame and between which said mainframe is positioned, means including a link member connected to each truck frame and to said main frame for preventing lateral movement of -said truck frames with respect to said main frame, and an inverted equalizer spring connected to said main frame and to said link members.

'1. In a tractor,.a main frame, a pair of spaced truck frames s each movably connected to said main frame and between which said main frame is positioned, means including a link member connected adjacent one end thereof to each truck 05 frame for preventing lateral movement 'of said truck frames with respect to said inainJ frame, l each of said link members being pivoted on said main frame intermediate ,its ends whereby movement of the opposite end of each link member is always in a direction opposite to that of the truck frame to whichfthe .linkmember is ,connected, and anfinverted equalizer spring connected to said main frame and having its ends connected with said link members;

is positioned,vv means including a link member connected adjacent one end thereof to each truck frame for preventing lateral movement of said truck frames with respect to said main frame, eachof said link members-being pivoted on said main frame intermediate its ends whereby movement of the opposite end of each link member is always in a direction opposite to that of the truck frame to which the link member is connected, an inverted equalizer spring positioned under said main frame and having its ends connected with said link members, and means for pivotally connecting said spring to said main frame vfor movement about a substantially horizontal axis.

9. In a tractor, a main frame, a truck frame at each side of said -main frame and movably connected thereto, `a member connected to each truck frame and to said main frame to prevent lateral movement of each truck frame withl respect to said main frame, each of said members being movable by relative movement between said truck frames and said main frame, and an equalizer member. connected to said main frame and having its ends connected with said members.

10. In a tractor, a main frame, a frames, each hingedly connected to said main frame adjacent one end thereof, said hinge conynection including two widely spaced bearings,

one of which is positioned adjacent the longitudinal center line of said main frame to cooperate with another of said bearings for resisting lateral displacement of said truck frame with respect to said main frame, means including a link member pivotally connected to both said main frame and each truck frame adjacent the opposite end thereof to positively preclude said lateral displacement, and an equalizer bar pivotally connected to said main frame underneath thereof andhaving Aits ends connected to said r said truck frames, said-latter means including an equalizer member attached to said main frame intermediate its ends and lever members connected to'said main frame, said lever members exerting downward pressure 4on said .equali izer member.

12. In a tractor,`a main frame, spaced truck frames, means for supporting an end of said main frame on said truck frames, means for supporting an opposite end of said main frame on said truck frames, said latter means including a spring attached to said main frame intermediate its ends and adapted to .resist downward pressure at its ends, and members connected to said main frame and exerting downward pressure on the endsof said spring. y

13.v In a tractor, a main frame, spaced truck frames, means for supporting an end of said mainframe on said truckv frames, and means for supporting an opposite end of said main frame on said truck frames, said latter means including a lever member attached to said mainframe intermediate its ends, and link members connected .to said main frame and pressing downwardly on the'ends of said lever member.

'said main frame at a position above said spring, .andllink members connected to ,said main frame pair of truck 14. In a tractor, a mainframe, spaced truck frames, means for supporting an end of said main frame on said truck frames, and means for supporting `an opposite end of said mainframe on said truck frames, said latterY means including a lever member attached to said main frame intermediate its ends, link members connected to said main frame and exerting downward pressure on the ends of said lever member, and means connecting said link members to said truck frames.

`15. In a tractor, a main frame, spaced, truck frames, means for supporting an end of said main frame on said truck frames, and means for supporting an opposite end of said main frame on said truck frames, said :latter means including a lever member pivotally attachedl to said main frame intermediate its ends, link members pivotally attached to said main frame and exerting downward, pressure on the ends of said lever member, and means connecting said link memers to said truck frames.

16. In a tractor, a main frame, spaced truck frames, means for supporting an end of said main frame on said truck frames, and means for supporting an opposite end of said main frame on-said truck frames, said latter means includinga spring hanger, a spring mounted in said hanger, means for pivot-ally connecting said hanger to and pressing Adownwardly' on the ends of said spring.

17. In a tractor, a main frame, a pair of truck frames, each truck frame being at aside of said main frame, load supporting connections between the rear end of said main frame and said truck frames, a pair of rigid link members, each link member being adjacent a side of said main frame,4

means journaling each link member upon said 40 main frame at a point intermediate the ends of said link member so that s'aid link member has a front portion' and a rear portion, means connecting the rear portion of each link member to a truck frame for movement relative to said truck 45 frame, and an equalizer member connected to said main frame adjacent the front thereof and extending transversely with respect to the longitudinal axis of said mainframe and to said link members, the ends lof said equalizer member ter- 50 minating adjacent the front portions of said link members and being 4connected to the front portions of said link members.

18. In a tractor, a main ira-me, a pair of truck frames, each truck frame being at a side of said4 55 main frame, load supporting connections between the rear end of said main frame and said truck frames, a pair of rigid link members, each link member being adjacent a side of said main frame,

means journaling each link member upony said main frame at a point. intermediate the ends of said link member so that said link member has a front portion and a rear portion, means connecting the rear portion of each link member to a truck frame for movement relative to said truck portions of said link members so that downward pressure isexerted on theends of said equalizer 'member by said front portions of said link memy bers.

19. In a tractor; a main frame; a pair of truck frames, each truck frame being at a side of said main frame; load 'supporting connections between the rear end of said main frame and said truck frames; an equalizer member connected to said main frame adjacent the front thereof; and link means adjacent each side of said main frame providing a connectionbetween said main frame, the truck frame at the side of said main frame and an end of said equalizer member; each of said link means consisting essentially of a single rigid member having one point of connection directly to said main frame, another point of connection to said truck frame and a third point of connection directly to an end of said equalizer member.

20. In a tractor, a main frame, a pair of truck frames, each truck frame being at a side of said main frame and hinged thereto, a pair of link members, each link member being journaled on said main frame at an intermediate point in its length,.an equalizerv bar connected to said main to said main frame, to the truck frames and to the ends of said lever member, the connections of said link members to the ends of said lever member causing the link members to exert a downward pressure on the ends of said lever member.

22. In a tractor, a main frame, spaced truck frames, means hingedly supporting an end of said main frame on said truck frames, and means supporting the opposite end of said main frame on said truck frame, said latter means including an equalizer bar extending transversely with respect to the main frame and mcvably attached to the main frame intermediate its ends, and link members each connected to said main frame intermediate its ends and at one end to a truck frame, the other end of each link member being connected to an end of said equalizer bar,the connections of said link members to the ends of said equalizer bar causing the link members to exert a downward thrust on the ends of said equalizerj bar.

23. In a tractor, a main frame, a track frame on `one side of the main frame, a second track frame on the other side of said main frame, a hinge connection between said main frame and each of said track frames, an equalizer member 

